Two part cartridges with force biasing by printer
A two part cartridge having a photoconductor part (1) and a toner part (5) having no force biasing element on either part. The two parts fit together so that a developer roller (7) in the toner part contacts a photoconductor drum (3) in the other part. When the two parts are installed in a printer the cover (50), when closed, brings a spring (62) into contact with one side of the toner part while the frame (F) of the printer blocks movement away from the cover. An advantage of the two part cartridge is that the toner part can be replaced without replacing the photoconductor part. Members on the cartridge for force biasing are avoided and the need for training or skill to latch the parts together is avoided.
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This application is a continuation of U.S. application Ser. No. 10/195,270, filed Jul. 15, 2002 now U.S. Pat. No. 6,678,489, and titled Two Part Cartridges with Force Biasing by Printer.
TECHNICAL FIELDThis invention relates to electrophotographic imaging and, more particularly, relates to separate replaceable cartridges for toner and photoconductor, which are pressed together for good operation when installed in the imaging device.
BACKGROUND OF THE INVENTIONElectrophotographic toner cartridges are often joined in two sections pivoted to one another so that a developer roller can be pressed against a photoconductor drum with controlled pressure. The controlled pressure is provided by permanently installed springs stretching between the two sections. The two sections are not normally separated, so such cartridges can be said to be one part cartridges.
Such one part cartridges have the advantage of having the spring force installed at the factory manufacturing the cartridge and having a relatively short duration during which the springs need provide the correct pressure, since the entire cartridge is refurbished (or discarded) after use of the original cartridge. Such one-piece cartridges have the disadvantage that the springs must be included on each cartridge. Also, for such one piece cartridges, replacement of the toner with a new section having the toner is not practical since the sections are not readily separated.
Two part cartridges are known in which a part having the toner is readily separated from a part having the photoconductor drum, since they are not pivoted to one another. To install such two part cartridges for imaging, they are manually brought together by the operator, and then the operator activates a latching mechanism, such as a resilient latch or a lever of some kind, to force the two parts together with the appropriate pressure for imaging.
A disadvantage of such known two part cartridges is that the forcing mechanism must be on one or both of the two parts and therefore adds to supplies costs, as both of the two parts are typically replaceable as they are worn (in the case of the photoconductor and other physical parts) or expended (in the case of the toner). Another disadvantage is that operator involvement requires training or some skill, and requires an overall design which permits the operator to reach the latching mechanism and activate it or deactivate it. A further disadvantage is that the force biasing elements require some space in the body of the imaging devide.
DISCLOSURE OF THE INVENTIONThis invention provides for two part cartridges which have no mechanism to latch the cartridges together. Biasing force during use is provided from the cover of the imaging device when closed. The two parts need only have conforming external configurations so that they fit together, and require no space in the middle of the printer for a force biasing element. No operator involvement in forcing the two parts together is required except for inserting the cartridges in the imaging device and closing the cover of the imaging device. Although the biasing by the cover may be by a spring or springs more costly than springs or other forcing mechanism which might be on the parts, over the life of the imaging device the overall costs typically will be less.
The details of this invention will be described in connection with the accompanying drawings, in which
Referring to
The right side of part 5 has an upper guide stud 17 and a lower guide stud 19.
Part 5 has an upper handle 21, which can be readily grasped by an operator to pull part 5 away from part 1. Part 1 has a lower handle 23 which extends past part 5 when the two are combined (FIG. 2). Handle 21 and handle 23 can be grasped and pulled by an operator to pull out part 1 and part 5.
Since part 5 contains toner used for imaging, part 5 will be extracted and replaced with a replacement part 5 having toner more frequently than part 1 will be replaced. Part 1 will be extracted and replaced with a replacement part 1 when the photoconductor becomes deteriorated or when excess toner fills the compartment in part 1 for toner cleaned from the photoconductor 3 (such cleaning is standard).
Referring to
The action of the drive coupling and the gears shown will not be described in detail as they are essentially standard for imaging by driving known parts, not shown, including a toner adder roller and a toner mixing paddle, as well photoconductor drum 3 and the developer roller 7. Similarly, with reference to
Guide studs 17, 19 and 36 are external caps of DELRIN 500 polyacetal, a hard plastic, mounted on shafts integral with the body of part 5. The body of part 5 is made of polystyrene. Openings 17a, 19a (
Referring to
Mounted on the inside of cover 50 is one-piece housing 56, mounted to cover 50 by four screws, 58a-58d. Housing 56 has latching members 60a and 60b on opposite sides of cover 50. Primarily significant to this invention, housing 50 confines a leaf spring 62, having opposed bent ends 62a and 62b which extend past housing 56 at openings 56a and 56b on opposite sides of cover 50.
Housing 56 has integral, upward extending arms 57a-57d, which contact cover extensions 50a-50d. Screws 58a-58d are located in lateral, oval slots in housing 56. Integral with housing 56 on the left is a flat, pressing surface or “button” 64. When cover 50 is closed, latching members 60a and 60b are pushed leftward by arms 57a-57d acting on extensions 50a-50d. An operator pushing on button 64 overcomes this force and frees latches 60a and 60b to allow cover 50 to open.
Although spaced spring contacts as in the foregoing embodiment tend to minimize variations between printers from differences within accepted tolerance, clearly a single leaf spring mounted in the center is an alternative. Of course, two spaced coil springs is an alternative. Other members can provide resilience, such a urethane rubber pads. Instead of spaced contacts, a wide, resilient pad could provide the force biasing. In sum, this invention is not deemed limited by the details of the biasing member operating from the cover. The cover could provide a linkage to move a separated biasing member with movement of the cover, although this normally would be more expensive than simply mounting the biasing member on the cover.
A modification of the foregoing under consideration is to replace spring 62 by two, separate leaf springs, each originating near the middle of cover 50 and terminating as shown in the foregoing.
Although the cover in the foregoing embodiment opens from the bottom, a clear alternative would be to hinge the cover on the bottom so that it opens from the top.
Other variations and alternatives will be readily apparent or can be anticipated.
Claims
1. A two part imaging cartridge in which one part is in contact with the other part by at least two guide studs on one of said two parts entering at least two guide channels on the other of said two parts, one of said two parts containing a developer member and the other of said two parts containing a photoconductor, said guide channel being directed to bring said developer member in contact with said photoconductor and having an open end for said entry of said guide stud;
- said two parts having no force biasing member on either part for force biasing said photoconductor against said developer member, force biasing for imaging being dependent upon external force being applied to said two parts;
- said part containing a developer member having at least one of said two guide studs.
2. The two part imaging cartridge of claim 1 wherein said two guide studs are on one side of one of said two parts.
3. The two part imaging cartridge of claim 2 wherein said two guide channels are one side of the other of said two parts opposite said two guide studs.
4. The two part imaging cartridge of claim 1 wherein said two guide studs comprise an upper guide stud and a lower guide stud on one side of one of said two parts.
5. The two part imaging cartridge of claim 4 wherein said two guide channels comprise an upper guide channel and a lower guide channel on one side of the other of said two parts opposite said two guide studs.
6. The two part imaging cartridge of claim 1 further comprising a third guide stud on one of said two parts entering a third guide channel on the other of said two parts.
7. The two part imaging cartridge of claim 6 wherein two of said guide studs are one side of one of said two parts and enter guide channels on one side of the other of said two parts.
8. The two part imaging cartridge of claim 7 wherein a third of said guide studs are on a second side of one of said two parts and enters a guide channel on a second side of the other of said two parts.
9. The two part imaging cartridge of claim 1 further comprising a first handle on one of said two parts.
10. The two part imaging cartridge of claim 9 further comprising a second handle on the other of said two parts.
11. A two part imaging cartridge in which one part is in contact with the other part by at least two guide studs on one of said two parts entering at least two guide channels on the other of said two parts, one of said two parts containing a developer member and the other of said two parts containing a photoconductor, said guide channels being directed to bring said developer member in contact with said photoconductor and having an open end for said entry of said guide studs;
- said two parts having no force biasing member on either part for force biasing said photoconductor against said developer member, force biasing for imaging being dependent upon external force being applied to said two parts;
- said part containing a photoconductor having at least one of said two guide channels.
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Type: Grant
Filed: Dec 15, 2003
Date of Patent: Apr 12, 2005
Patent Publication Number: 20040126133
Assignee: Lexmark International, Inc. (Lexington, KY)
Inventors: Philip Scot Carter (Lexington, KY), Julia L. Fain (Lexington, KY), Mark Duane Foster (Lexington, KY)
Primary Examiner: Arthur T. Grimley
Assistant Examiner: Ryan Gleitz
Attorney: Joseph Arrombide
Application Number: 10/736,355